The artists, who had not revealed their identities, lugged the statue of Snowden to Fort Greene Park before sunrise.

They then attached it to the Prison Ship Martyrs Monument, which pays tribute to Revolutionary War soldiers, Animal New York reported.

"Fort Greene's Prison Ship Martyrs Monument is a memorial to American POWs who lost their lives during the Revolutionary War," the artists told Animal New York. "We have updated this monument to highlight those who sacrifice their safety in the fight against modern-day tyrannies."

But hours after the statue was installed, city officials covered the work up before removing and confiscating it.

"The erection of any unapproved structure or artwork in a city park is illegal," a parks department spokesperson told BuzzFeed News at the time.

The artists said that the sculpture was designed by an artist on the West Coast. The bust is made from a plaster-like substance commonly used in places like Las Vegas to create the look of Roman architecture, Animal New York reported.

The artists also used an adhesive that would hold the bust in place but that would not damage the monument.

The artists reportedly plan to display the Snowden statue at an art gallery, and in a statement issued earlier in the day said they hope to eventually get permission from city officials to temporarily feature it in a local park.

Snowden, meanwhile, remains in exile in Russia after divulging the U.S. government's secret collection of the public's phone records.